Air jet looms having suction conduits which move with the reed in the upstream and downstream directions (with respect to the direction of fabric movement) are in common use today, manufactured by a number of manufacturers. Typical or such looms are the Elitex P series of air jet looms manufactured by the Zbrojovka National Corporation of Vsetin, Czechoslovakia.
While such air jet looms are in general quite productive and efficient, there are a number of drawbacks associated therewith. One major drawback is the necessity of using outer or auxiliary binding yarns (ends) for removal of the waste fringe yarns. Typically 8 auxiliary binding ends are used first to bind and then to carry away the fringe yarns. These auxiliary ends comprise a great deal of waste, and require a number of machine elements to handle and dispose of them.
Another significant disadvantage of conventional air jet looms of the type described above is the necessity for relatively long fringe lengths. For certain fabric widths up to 9% of the filling yarn length becomes waste. A related disadvantage of prior art commercial structures is that errant filling yarns or picks may shoot outside the suction nozzle entirely, thereby producing fabric quality problems caused by slack filling yarns, and often leading to shutdown of the loom for adjustments.
According to the present invention the drawbacks associated with conventional air jet looms of the type described are eliminated or minimized. In particular, according to the present invention the auxiliary binder ends are eliminated entirely, the amount of filling fringe waste is reduced by about 30-40%, and the probability of errant picks not being captured by the suction nozzle is virtually eliminated.
The problems inherent in commercial air jet looms of the type described above are dealt with by providing a particular interaction and operation between the fringe cutting mechanism and the suction conduit, and by redesigning the suction conduit nozzle end.
According to the present invention, the fringe cutting mechanism includes a cutting element which is mounted so that it is upstream of the temple (with respect to the direction of fabric movement), and adjacent the suction conduit nozzle when the suction conduit is in its downstreammost position. The reed, and the actuating arm associated with the loom for effecting the fringe cutting, are provided with surface means such that the fringe cutter is actuated in response to movement of the reed in the downstream direction (triggering occurring just before the reed reaches its downstreammost position). In providing such a structure it is possible to utilize the already existing suction conduit as the sole means for carrying away the waste fringe, while simultaneously eliminating the auxiliary binder ends and their associated heddles, drop wires, tension discs, yarn packages, package supports, and take-up wheels, all of which are normally associated with such a loom.
Further, according to the present invention the fringe cutting mechanism includes a cutting block which the rotating arm--with cutting element--moves into operative association with, plus an optional but preferred fringe lifting means which extends outwardly from the block in operative association therewith. The lifting means preferably comprises a stiff wire which provides a ramp surface for guiding fringe to be cut into proper operative association with the cutting block.
The nozzle of the suction conduit according to the present invention is designed so that it has an entrance diameter significantly greater than the entrance diameter of the conventional nozzle, yet has a throat diameter which is less, the conical mouth of the nozzle providing a taper between the entrance and the throat. The larger entrance adequately covers the exit aperture of the confuser so that errant picks will be guided into the high suction throat, and the reduction in throat diameter increases the nozzle air speed and thus the tension on the leading ends of the filling yarn. Further, since the auxiliary binder ends and heddles associated with conventional looms of this type are no longer necessary, the nozzle entrance may be placed significantly closer to the confuser exit. The closer nozzle location and increased filling yarn tension work together to permit minimizing the filling yarn fringe length.
It is the primary object of the present invention to provide a shuttleless loom having minimized material waste, and maximized reliability and efficiency. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.